This invention relates to a pouch form, fill, seal machine and particularly to a machine that can easily be adjusted to accommodate pouches of various lengths, the length being the dimension in the direction of movement of the pouch on the machine.
Pouch form, fill, seal machines have been known for many years. In such machines, a continuous web is folded in half over a generally triangular plow. The folded web is fed around a drum having heated lands, the heated lands making transverse seals of thermoplastic material from which the pouch is formed or laminated. That sealed web is fed to a filling drum that has uniformly spaced lands around its perimeter. A registration device operating from a registration mark printed on the web maintains a registration of the seals centered on the lands of the filling drum. In the filler, the pouches are filled. Immediately thereafter, they are sealed and cut into individual pouches and fed to cartoning machines.
Such machines are suitable for forming, filling, and sealing only one size pouch. To change to another size pouch would require, among other things, a different sealing drum and a different filler. The change parts are so expensive that it is pointless to attempt to run different sizes of pouches and, hence, different products on one machine. A manufacturer with a product mix requiring different sizes pouches will have a different size machine for each size pouch.
Manufacturers having a varied product mix that is packaged in various sizes of pouches would be greatly benefitted by a machine capable of running various sizes of pouches with the conversion being capable of being made from one size to the other without great expense.
Registration of the pouch seams to a cutting knife is very important. Not only must the cut be made on the seam to avoid pouch rupture, but it is also important to make the cut on the center of the seam between pouches so that the edges on each side of the pouch are of a uniform width to insure an aesthetically appealling pouch.
With an adjustable pouch machine, the wide variety of sizes of pouches and thicknesses of pouch, as determined to some extent by product density, makes registration a problem. Further, if the pouch is unprinted, a special operation would be required to print a registration mark on the pouch if current registration systems are to be used.